ALK and neuroblastoma: As a result, we found that withdrawal of the ALK inhibitors after 48 h of treatment allowed for re-growth of NB cells to occur (Fig. 1h; Supplementary Figure 1e, 1f, 1g), suggesting that the ALK inhibitors are unable to completely suppress tumour growth, and that a novel therapeutic strategy is therefore required for effective induction of cell death, but not cell-cycle arrest, in ALK-driven NB cells.